Dependence of NTR1 expression and cell proliferation on extracellular pH. Modulation of (A) protein expression of NTR1 and (B) cell proliferation under acidic, normal, and alkaline extracellular conditions in BxPC‐3, PANC‐1, and MIA PaCa‐2 cells. Data are presented as mean ± SD of duplicate measurements of relative fluorescence intensities and cell numbers, respectively. In both tests, all differences of values at acidic and alkaline pHe to normal pHe are statistically significant, with exception of expression of NTR1 in MIA PaCa‐2 cells.